The present invention is related to a transmission arrangement for a vehicle, and more particularly to a transmission arrangement which is located at the rear end of the vehicle for improved servicing and which has an axially compact relationship between the major components thereof.
Heretofore, transmission and power train arrangements for vehicles such as large earthmoving tractors have been excessively long because it has been a problem to align the longitudinally oriented engine driven output shaft, the multispeed transmission, and a suitable transfer gear train with the transversely oriented bevel gear and cross shaft assembly. Since the bevel gear delivers power to the cross shafts, the opposite steering clutches and brakes, the final drives, and the associated sprockets or wheels that propel the vehicle, it is normally of large diameter and substantial clearance is required for proper mounting thereof. Particularly, the axis of the bevel gear and cross shafts must be elevationally offset from the axis of the engine driven output shaft in order for the various elements to clear one another. In such instance at least one transfer gear train is provided between the output of the transmission and the bevel gear driving pinion and this requires considerable space. Another disadvantage of these long transmission and power train arrangements is that they often extend rearwardly and outwardly to a point where the elements thereof are exposed to possible damage or to a point where they interfere with the proper placement and mounting of auxiliary equipment on the rear of the vehicle.
Another problem concerns the difficulties associated with servicing transmission arrangements of the above noted type. In the past they have been located in the central portion of the tractor immediately behind the engine so that it has been necessary to disconnect and remove substantial portions of the operator station and/or associated tractor components in order to provide access to the transmission arrangement and to allow lifting or lowering of major elements thereof from within the confines of the tractor for separate servicing.